An adaptive threshold based scheduling policy for ATM networks

Asynchronous transfer mode (ATM) has been adopted as a world-wide standard for the broadband integrated services digital network (B-ISDN). ATM enables a single high-performance network to carry a variety of traffic (e.g., data, video and voice) in an integrated manner. The different types of traffic usually have different and sometimes conflicting quality of service (QOS) requirements, all of which should be met by the underlying network at the same time. In this paper, we propose and evaluate the performance of a threshold policy for scheduling traffic in an ATM switch. The results suggest that by an appropriate choice of the threshold values, the policy can meet the quality of service requirements of the different traffic classes even at very high utilizations. To accommodate varying load conditions, an adaptive version of the policy, that dynamically adjusts the threshold values, is also described and evaluated.